This invention relates to apparatus for immobilization of a part of a person's limb. Such apparatus are generally used for orthopedic treatment of limb injuries.
Depending on the nature of the injury, the affected part of the limb may be placed in a cast for a period of time ranging from a few days to many months. The casts that are most commonly used at the present time are made of plaster of paris or plastic with reinforcing fabric. Such casts are usually formed over the patient's limb and they usually include some padding materials to prevent abrasion to the skin on the surfaces of contact. Such casts have the following advantages: (1) They do not provide sufficient ventilation for cooling and removal of moisture in warm weather, during active physical exercise, or for limb injuries that include injuries of the skin. (2) If one such cast gets wet, it is very troublesome to dry because the padding materials, which in most cases are thick pads of cotton, absorb water readily. (3) If such a cast gets dirty, it is very difficult to clean. (4) The skin under the cast cannot be cleaned easily, therefore the skin becomes dirty and itchy after a week or so of wearing such a cast. (5) Such a cast is usually so thick that it makes the covered part of the limb uncomfortably hot in warm weather. (6) Such a cast is usually so thick that the patient cannot wear his regular clothes over the cast in cold weather.
It is therefore highly desirable to have an apparatus to perform the function of a cast for immobilization of a part of a limb but not have the disadvantages described above.
There have been several attempts to make such an apparatus; however, most of these attempts resulted in apparatus that cannot be made to fit the limb very comfortably. Therefore, the apparatus can only be used for very short periods of time (such as in the ambulance on the way to the hospital). The ones that can be made more comfortable can only be made to fit a very narrow range of sizes and shapes. Moreover a splint of the latter type that is made for a right limb cannot be used on a left limb, and vice versa. The physician must therefore keep an inventory of many such apparatus to be able to fit most patients.
Some of the apparatus in the prior art have a wire mesh which can be bent into a generally cylindrical shape to fit over some parts of the limb. Examples of such apparatus include a splint described in U.S. Pat. No. 2,060,001 issued to Attwood et al, and a surgical splint described in U.S. Pat. No. 1,512,558 issued to Montgomery. Wire meshes are generally difficult to stretch; so an initially-flat piece of wire mesh can only be bent into shapes such as cylinders and cones, but it cannot be bent into a saddle-shape which is needed to fit comfortably over wrists and ankles.
The wrist and ankle are among the most frequently injured parts of the body. To immobilize a wrist or an ankle, the apparatus must hold the wrist/ankle in a fixed position relative to the parts of the limb in the proximal and distal directions. The part of the limb in the proximal direction is, in both cases, long, relatively insensitive, and easy to hold onto. But in both cases, the part of the limb in the distal direction (the hand, distal from the wrist, and the foot, distal from the ankle) are short, highly sensitive and difficult to immobilize. An apparatus for immobilizing the wrist and ankle must therefore have special provision for a comfortable fit over the hand and the foot. One embodiment of the present invention provides an adjustable collar that enables the apparatus to grasp the hand and the foot comfortably. Other embodiments of the present invention use ordinary clothing materials to help grasp the hand and foot (a glove for the hand, and a shoe for the foot).
It is highly desirable to have an apparatus that
does not have the disadvantages of the plaster or plastic splints, PA1 is sufficiently comfortable that the apparatus can be worn over long periods of time, PA1 can be adjusted to fit limbs over a wide range of sizes and shapes, and PA1 can be adjusted to fit both the left limb and the right limb.
The present invention provides such an apparatus. This apparatus shall be referred to as a "splint".